3.4. The thermal properties of ice cream with GWL
The thermal properties associated with ice crystal-melting of ice
cream with and without GWL were determined by differential
scanning calorimetry (DSC). Fig. 2 shows the typical DSC curves for
the ice crystal-melting curves. The enthalpy for the ice crystalmelting
of 0 g kg1 GWL, 50 g kg1 GWL, 100 g kg1 GWL,
150 g kg1 GWL and 4 g kg1 CMC was 7.16, 6.73, 6.25, 4.43 and
9.76 J/g, respectively. Addition of GWL decreased the enthalpy
values associated with the ice-melting transition. The decrease in
enthalpy value might have two possible reasons: the decrease of
the final moisture content and the decrease of freezable water in
the sample. However, the addition of GWL (800 g kg1 moisture
content) increased the final moisture content; therefore, the
moisture content was not the factor for the reduction in the
enthalpy. Vittadini and Vodovotz (2003) reported that the enthalpy
of ice-melting transition had a positive correlation with the amount
of freezable water in the tested sample. Our data indicated that the
addition of GWL significantly decreased the amount of freezable
water in ice cream and that GWL had the ability to hold water and
thus increases the melting rate and freezable water in ice cream.